Electrostatic condenser



Nov. 29,1932 Y RUBEN snacmqs n'nc cqunsusnn 0:1 am Filed Au ."22. 1927 iATTORNEYS Reissuecl Nov. 29, 1932 UNITED STATES PATENT OFFICE l SAMUELRUBEN, ormiw ROCHELLE, NEW" YORK,

TO RUBEN CONDENSER COMPANY, OF NEW ROCHELLE, NEW YORK, A CORPORATION OFDELAWARE ELECTROSTATIC CONIIJIEJNSER-v Original No. 1,714,319, dated May21,1929, Serial No. 214,777, filed August 22,

filed May 5, 1931.

This invention relates to electro-static condensers; its object is toprovide a high ca-- types, the gas layer polarized cell type and theelectrolytically formed film layer type. The polarized cell typeoperates below the decomposition potential of the solution by employingthe polarized effect of a gas layer at its electrode surface; the lattertype, as exemplified by those using aluminum electrodes, employs acurrent-blocking film of a composite gas layer and hydroxide or oxidefilm; they use a film-forming compound either in the form of a solutionor a paste mixture, the ohmic resistance of the electrolyte beingrelatively high.- For uses on power filter circuits where efficiency andhigh capacitances are desirable, both ofthese devices have undesirablelimitations. The condenser of my invention has the equivalent ofametallic conductive path, that is by the finelydivided conductive metalparticles, such as copper,

, which are in such close contact as to give a low internal resistance.It is of the film-forming type having a specific kind of electrolyte,which is a film-forming composition, the electrodes being separated by aporous retiform spacer. The combination gives a condenser of largeelectrostatic capacity and high efliciency.

I have found that copper powdermlxed with a saturated solution ofpotassium fluor- .ide contacting with the electrodes forms a film whichis a current-blocking layer when connected as the anode in a circuit,and that an efficient condenser is made up of copper plate electrodeshaving therebetween a thin layer of-such a mixture. A current-blockingcoating is quickly formed about the surface of the copper particles withthe dlschargeof current, thus giving a wide contact resistance area atthe electrode surfaces. To malntain a uniform salt conductivity a slightamount 1927. Application for reissue Serial No. 535,271.

of glycerin or other hygroscopic material may be added. To insure thecontinued even distribution of the electrolyte, this element ispreferably spread over-the surface of a suitable porous or reticularspacer, such as a cotton gauze material preferably dipped in paraffin.

ASSIGNOR, IBYj MESNE ASSIGNMENTS,

As the electrolyte used enables the quick reformation of after itspenetration by an excessive discharge, the device is self-healing and inaddition to being adapted as a condenser, is also well adapted fof useas a lightning arrester.

Reference is made to the accompanying drawing showing one embodiment ofthe invention,-in which Fig. 1 shows a fiat plate form'of condenser andFig. 2 a condenser having its elements in coil form. In Fig. l, 1 and 4represent copper plate electrodes and 3 a cloth spacer which isimpregnated With an electrolyte containing finely divided copperpowder.On the adjacent surfaces of the electrodes an electrolytically formedfilm covers the areas contacting with the electrolyte. In Fig. 2 thoseelements are represented by corresponding figures, 2 showing theelectrolyte applied to the spacer between the electrodes.

The condenser has been described as em- Ving copper electrodes with afilm-forming electrolyte-containing copper particles. How-- ever, othermetals, such as aluminum, magnesium, silver and tantalum, are alsoapplicable with small particles of metal mixed with a suitableseparating film-forming electrolyte' An electrolyte ofa fluoride setforth is suitable for use with any of the valve metals mentioned butother film-forming electrolytes obviously may be used. With aluminum ortantaluman electrolyte of boric acid and a salt thereof may be used withwhich may be mixed, if desired, a. viscous material such as a.polyhydric alcohol, for example a glycolor a" glycerol. A specificexample of a suitable electrolyte for aluminum or tantalum is sodiumbicarbonate, boric acid and glycerine. With magnesium an electrolyte of-potassium chloride may be used advantageously. Any electrolytewhich'has been found prior to the present inventionfas being suitablewith any of thevalve metals setforth above is useful current-blockingcoatings in the condensers of the present invention since theincorporation in the electrolyte of fine particles of valve metal makesno special demands upon the specific characteristics of the electrolyte.Having described my invention, what I claim as new and desire to secureby Letters Patent, is: v

1. An electrical condenser comprising electrodes of a metal which willrespond to electrolytic'action in a manner to form a composite partiallysolid current-blocking film thereon having in surface contacttherebetween a mixture of fine particles of the same metal which willrespond to electrolytic action in a manner to form a current blockingfilm thereon and a film-forming electrolyte.

2. An electrical condenser comprising metallic plate electrodes whichwill'respond to electrolytic action in a manner to form a compositepartially solid current-blocking film-.

thereon having in surface contact therebe tween a mixture of fineparticles of the same metal capable of being film-formed and afilm-forming. electrolyte held in suspension by porous spacer material.a

3. An electrical condenser comprising metallic plate electrodes whichwill respondto said anode.

ite partially solid current-blocking film and a mixture of afilm-forming electrolyte and fine particles of the same metal from whichthe anode is formed in surface contact with In testimony whereof I afiixm signature.

- SAMUEL UBEN.

electrolytic action in a manner to forma composite partially solidcurrent-blocking film thereon having in surface contact therebetween amixture composed of fine particles of the same metal and a film-formingelectrolyte held in suspension by a reticular body.

4. An electrical condenser comprising metallic'plate electrodes whichwill respond to electrolytic action in a manner to form a curfluorideheld suspension by a reticular x body.

7. An electrical condenser comprising copper plate electrodes having insurface contact therebetween a mixture of small partidies of copper in asolution of potassium fluoride.

8. An electrical condenser comprising copper plate electrodes having insurface contact therebetween copper particles and an electrolyte ofotassium fluoride held under sus- V pension y a spacer in reticularform.

9. An electrical condenser comprising an anode of a metal which willrespond to electrolytic action in a manner to form a compos-

